CLEVELAND (Reuters) - Ohio Governor John Kasich on Wednesday stayed the execution of convicted killer Ronald Phillips to assess whether Phillips's non-vital organs or tissues can be donated to his mother or possibly others.

Phillips, 40, was scheduled to be executed Thursday for the 1993 murder of 3-year-old Sheila Marie Evans. But Kasich granted a stay until July 2 to allow medical experts to assess whether Phillips's non-vital organs or tissues can be donated to his mother or others.

Phillips's mother needs a kidney, according to his attorney Timothy Sweeney.

"I realize this is a bit of uncharted territory for Ohio, but if another life can be saved by his willingness to donate his organs and tissues, then we should allow for that to happen," Kasich said in a statement.

Richard Dieter, executive director of the Death Penalty Information Center, said that inmates waiting on death row have donated non-vital organs such as kidneys before, but a stay of execution has never been granted to allow it.

"I've never heard of a case exactly like this," Dieter said. He said U.S. inmates are not allowed to donate organs after their executions.

Kasich's office said that if Phillips is found to be a viable donor, the procedures would be performed and he would be returned to death row to await his new execution date.

Phillips had been scheduled to be the first person executed in the U.S. using a combination of the drugs midazolam and hydromorphone. The state needed to use the drug combination because it didn't have enough of the drug pentobarbital.

Kasich, a Republican, has commuted the sentences of four men on death row to life in prison without parole since 2011. Ohio has executed three men this year and there are 146 men and one woman on the state's death row.

The U.S. has executed 34 prisoners so far this year, according to Dieter.